1. Field of the Invention
The present invention relates to a light emitting diode (LED) lamp, and more particularly to an LED lamp incorporating a heat sink and an electric fan for improving heat dissipation of the LED lamp.
2. Description of Related Art
As an energy-efficient light, an LED lamp has a trend of substituting for the fluorescent lamp for indoor and outdoor lighting purpose; in order to increase the overall lighting brightness, a plurality of LEDs are often incorporated into a signal lamp, in which how to efficiently dissipate heat generated by the LEDs becomes a challenge.
Conventionally, an LED lamp comprises a cylindrical enclosure functioning as a heat sink and a plurality of LEDs mounted on an outer wall of the enclosure. The LEDs are arranged in a plurality of lines along a height direction of the enclosure and around the enclosure. The enclosure defines a central through hole oriented along the height direction thereof. When the LEDs are activated to lighten, heat generated by the LEDs is dispersed to ambient air via the enclosure by natural air convection.
However, in order to achieve a higher lighting intensity, the LEDs are arranged into a number of crowded groups, whereby the heat generated by the LEDs is concentrated at discrete spots, which leads to an uneven heat distribution over the enclosure. The conventional enclosure is not able to dissipate the locally-concentrated and unevenly-distributed heat timely and efficiently, whereby a heat accumulation occurs in the enclosure easily. Such a heat accumulation may cause the LEDs to overheat and to have an unstable operation or even a malfunction.
What is needed, therefore, is an LED lamp which can overcome the above-mentioned disadvantages.